Why do my camellia flower buds turn brown and/or drop off of the plant before opening?

This is a common problem known as bull nose or bud drop and can be caused by several factors:
• Large fluctuations in temperature. Camellias perform best planted in areas with uniform moisture and that are not too wet or too dry.
• Freezing temperatures.
• Hot weather during the fall or spring, which may encourage shoot growth and cause the plant to drop its flower buds. Avoid planting varieties that bloom late in the spring and plant in a shadier, cooler location.
• Other plant stresses due to a lack of nutrients, poor soils or drainage.
• Camellia bud mites. They cause buds to develop slowly and either open late or fall off before opening.